I have QA1 Coilover in the front on my Firebird. I would like to know what size of a spring is used on it. Also, what is a suggestsed spring rates for alittle more autoX. I would like to get a stiffer rear spring without alot of lowering.

 

THe QA1's arent really suited towards handling. You might wana re consider what shock your using.

 

To answer your questions, look on the spring for some markings. The rate is usually coded on there. If it's not there, contact QA1 or whoever makes/sells them and ask them what the rate is.

Typical AX rates for the 4th gen F-body is around 500 front give or take 50lbs and in the rear about 125-150. That's a rough guide.